[Important!!]
We suggest that you do not download the firmwares using your DS/DSi console, the cards won't work in case of an DS/DSi firmware update.
R4/R4i/R4i SDHC 3DS: http://www.r4i-sdhc.com/downloade.asp
R4i Gold 3DS: http://www.r4ids.cn/r4i-download-e.html
R4/R4i Ultra: http://www.r4ultra.com/download.htm
Acekard 2i: http://www.acekard.com/download.php
R4iTT: http://www.r4itt.net/?c=gamekernel
Supercard ds onei: http://eng.supercard.sc/manual/dsone/evolution/download.htm
Supercard ds two: http://eng.supercard.sc/manual/dstwo/download.htm
PS3 Break: http://www.ps3break.com/download/
If you could not find firmwares for your flash card, simply go to http://www.linfoxdomain.com/nintendo/ds/
R4i SDHC